Freecycle
Something I've been meaning to do for a while and don't think I have, is to plug Freecycle. You give away stuff you no longer need, or pick up a freebie off the list. It reduces landfill and gives you a chance to meet exciting (and sometimes weird) new people. A lot of our stuff is going that way! Curtains, old electrical equipment, you name it, someone will take it!
What's even better is that I've just discovered there's one in Melbourne. Having given away all our stuff here, maybe we'll be able to get the karma back and get it for free over there!